1. Technical Field
The present invention relates in general to computer networks, and in particular, to a network processor for managing network traffic that uses updateable software managed trees for processing frames without disrupting policy enforcement.
2. Description of the Related Art
Computer networks have evolved to a point where switch routers are insufficient to handle complex network a routing and filtering requirements. Network processors, such as the International Business Machines (IBM) Network Processor (NP) have been developed to fill this need. Utilizing a connection similar to that of a network switch, an NP provides a level of control and flexibility that surpasses that of the network switch. Parallel lookup operations can be performed on a frame, complex modifications can be performed on packets, and policies can be managed at complex levels. Multiple processors are used to achieve a very high frame processing throughput.
Instructions for managing frame routing in an NP, known as xe2x80x9cpicocode,xe2x80x9d reside in memory but are directly used by the hardware to efficiently process frames according to a fixed set of rules. The rules are entered by administration software and compiled into picocode that drives the logical engines for controlling frame routing, frame filtering and Quality of Service (QoS) requests.
Two types of classifier trees can be used to implement the frame processing commands: Software Managed Trees (SMTs) and Fixed Match Trees (FMTs). SMTs provide the capability of performing operations on ranges, while FMTs only apply to a specific values i.e.
Media Access Control (MAC) layer addresses. The advantage of SMTs is the support of range operations that are required to perform such functions as Internet Protcol (IP) sub-netting, the disadvantage is they cannot be easily updated on-the-fly. Since the SMT is compiled from a set of complex rules, it cannot be updated by changing a single leaf. The entire SMT needs to be recompiled and downloaded to a pico-processor. Therefore, the rules implemented in the SMT are typically static. As such, when it is necessary to change the rules in an SMT, the download process will be time consuming. During this time, the NP still must maintain proper protocol processing.
The present disclosure provides a method and system for updating SMTs so that protocol processing is not disrupted.
The objective of updating software managed trees (SMTs) so that protocol processing is not disrupted is achieved in a method and system for updating an existing frame classifier tree within a network processing system that includes plurality of network processors and at least one control point processor. The method builds a classifier tree on the control point processor, specifies a subset of network processors as download targets for the classifier tree, downloads the classifier tree to the subset of network processors, and transfers control of frame processing to the classifier tree from the existing frame classifier tree by changing active tree pointers within the subset of network processors.
All objects, features, and advantages of the present invention will become apparent in the following detailed written description.